[pics] Which Panel Is Darker? [Optical Illusion]

[6Foot2]

http://gyazo.com/e6f71cd7afbdbefca3b29071698229ee.png

[RabbieBurns]

however if you do the inverse, and cover up the top and bottom and only leave the two middle bits, you can see they are indeed two separate colours.

[synaesthesia]

Well yes that's the idea of an optical illusion - it's not what is actually there, it's what your eyes/brain are interpreting as correct. As the join/middle cannot be seen when covered, our eyes make best judgement.

[Hightower]

But at @RabbieBurns is right. The bottom panel is lighter in the fact that the highlight at the middle join simply doesn't exist on the top panel. It would be a good illusion if both panels were exactly the same, but they are not.